ITEM TITLE:
Approval of Change Order to Harris Sand & Gravel in the Amount of $47,640 for Testing of Eccentric Ripper
SUBMITTED BY: Jason Miles, Capital Facilities Director
FISCAL NOTES:
Expenditure Required: $47,640
Unencumbered Balance: $4,118,920
Funding Source: Account 310-6450-58010 New Harbor GO 2015
RECOMMENDATION:
Approve a change order to Harris Sand & Gravel (HS&G) in the amount of $47,640 for testing of an eccentric ripper, a significantly less costly mechanical method to remove bedrock than blasting.
SUMMARY STATEMENT:
The project team has been investigating methods for reducing the cost to remove bedrock below water in the new harbor basin. A vibratory ripper appears to have potential for removing some of the rock at this project. After preliminary input and comments from Arcadis and the Engineer, RFP 15 was drafted with the intent to rip or break and remove sufficient quantity of bedrock to determine the ability and measure the productivity and cost-effectiveness for removing this bedrock by mechanical methods instead of blasting. Test locations were selected within the basin where removal of rock was planned or would be beneficial.
On August 16th we issued the draft RFP with Ripper Test Map (attached) for ripper testing services to HS&G for review of scope, completeness and comments. HS&G distributed the RFP to Western Marine Construction (WMC). We did not receive any comments except that HS&G said they could work with the draft. Last Friday HS&G emailed a proposal (see attached) that lacked some information or needed clarification. Arcadis coordinated with HS&G to resolve questions about their proposal. HS&G responded with the additional information. HS&G emphasized that the next favorable tide cycle is Sept. 16 thru 18, and they need at least one week before the test cycle to prepare the equipment.
Staff recommends that City Council approve a change order to HS&G for an amount not to exceed $47,640 to perform the following scope of work:
1. Mobilization, demobilization, equipment set up, labor, equipment, expendables, surveying, other support work and coordination with Western Marine Construction Inc. (WMC) to operate a Model X60 eccentric ripper to remove bedrock in the west harbor basin referred to as “West Outcrop”. Two proposed areas are outlined on the attached conceptual drawing.
2. Coordination with WMC for use of the excavator/ripper equipment package, access via the west breakwater and working within WMC’s basin construction area.
3. Mob/Demob, equipment set up (HS&G and WMC): Lump Sum $30,000
4. WMC Link Belt 800 Excavator & X60 ripper with fuel and operator: 12 hours @ $873/hour = $10,476
5. HS&G Hitachi ZX470 Excavator with fuel and operator: 8 hours @ $353/hour = $2,824 (if Cat 328 Excavator is used, rate is $259/hour but production is less)
6. GPS surveying to determine quantities: 8 hours @ $175/hour = $1,400.
7. Contingency, if authorized by Owner’s Representative, for additional time for tasks 4-6 @ 20% of $14,700 = 2,940.